JP2000248112A - Thermosetting resin molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin molding material which has good heat stability and good filling properties in molding by injection molding machines and the like. SOLUTION: This thermosetting resin molding material is obtained by adding an aqueous dispersion of a metal soap to a molding material obtained by adding an inorganic or organic filler to a thermosetting resin as an essential component, heating and kneading and then pulverizing the same. The aqueous dispersion of a metal soap is preferably added in an amount of 0.1-1 wt.% in terms of the metal soap based on the total amount of the molding material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting composition having good heat stability and good filling properties in molding by a molding machine having a screw-type preheating section (plasticizing section) such as an injection molding machine. The present invention relates to a conductive resin molding material.

[0002]

2. Description of the Related Art Conventionally, in molding by a molding machine having a screw-type preheating section (plasticizing section) such as an injection molding machine,
In the case of thermosetting resin molding material, when the molding material is transferred between the screw and the inner wall of the cylinder, and further in the injection molding, when the tip of the nozzle is further transferred, if the slipperiness is poor, the shear heat is large and the heat stability is high. Insufficiency sometimes caused the molding material to harden in the cylinder and make molding impossible.

As a countermeasure for this, for example, Sho 46-3250
As disclosed in JP-A No. 3 (1993) -32, a solid oily substance (for example, powdered metal soap) is secondarily added to a molding material to improve the slipperiness and improve the thermal stability of the molding material. A method of improving has been conventionally performed. However, when a molding material is manufactured or when there is a step of transporting the molding material by air at the time of injection molding, a problem that this metal soap scatters and impairs the original effect often occurs. It was necessary to increase the amount of addition.

[0004]

DISCLOSURE OF THE INVENTION The present invention is to prevent a solid oily substance added for imparting thermal stability from being scattered in a molding material by air or the like, and to provide a screw type preheating section (plasticizing section). The purpose of the present invention is to provide a thermosetting resin molding material having good thermal stability and good filling properties in molding by a molding machine having a modified part.

[0005]

SUMMARY OF THE INVENTION The present invention provides an aqueous dispersion of a metallic soap in a molding material obtained by adding an inorganic filler and / or an organic filler as an essential component to a thermosetting resin, kneading the mixture, and pulverizing the mixture. Is a thermosetting resin molding material characterized by being added.

[0006] The compounding material of the thermosetting resin molding material of the present invention comprises a thermosetting resin and an inorganic filler and / or an organic filler as essential components, and further includes, if necessary, a curing agent and a curing assistant. Be blended. Examples of the thermosetting resin include a phenol resin, an epoxy resin, a diallyl phthalate resin, an amino resin, and a polyester resin. As the inorganic filler and / or the organic filler, glass fiber, mica, clay, calcium carbonate, inorganic substances such as aluminum hydroxide, wood flour, pulp, thermosetting resin cured product, cloth pulverized material, and organic substances such as nylon. No. The curing agent and the curing assistant are appropriately selected depending on the type of the thermosetting resin. In addition, a release agent, a pigment, an elastomer for modifying the resin, or the like may be added.

The aqueous metal soap dispersion used in the present invention is obtained by dispersing a fatty acid salt of a metal other than an alkali metal such as zinc or calcium in water, and is, for example, trade name: FCO DISPER C, ZD (ADEKA FINE CHEMICAL CO., LTD.). And the like). The amount of the aqueous metal soap dispersion is preferably 0.1 to 1% by weight of the metal soap based on the whole molding material. If the amount is less than 0.1% by weight, the effect is not sufficient. If the amount exceeds 1% by weight, the appearance of the molded product is deteriorated, and the mechanical strength is also reduced.

[0008] The aqueous dispersion of the metal soap must be well dispersed when it is secondarily added to the molding material. From this point, the concentration of the metal soap in the aqueous dispersion of the metal soap becomes 1
0-30% by weight is preferred. If the amount is less than 10% by weight, the amount of water added to the molding material at the same time increases, and water may remain in the molded product, causing a decrease in thermal characteristics and a decrease in dimensional accuracy. If it exceeds, the dispersibility tends to be insufficient.

The effects obtained by using the aqueous metal soap dispersion mainly include the following two points. One is that the metal soap in the aqueous dispersion remains on the surface of the molding material and is not easily scattered by air or the like of the molding material. From this, there is no risk of scattering as compared with the case where powdery metal soap is added as it is secondarily, and therefore, a good effect can be obtained even with a small amount of addition. Another is improvement of the filling property. This is the Japanese
As in the case of JP-A-183383, this is an effect caused by the simultaneous addition of water by adding the aqueous metal soap dispersion to the molding material.

[0010] The thermosetting resin molding material of the present invention is obtained by uniformly mixing the ingredients of the molding material and then using a kneading machine such as a roll, a kneader, a twin-screw extruder alone or a combination of a roll and another kneading machine. By heating and kneading and crushing to obtain a molding material,
Then, the obtained molding material can be obtained by spraying the aqueous dispersion of the metal soap while stirring and mixing.

[0011]

EXAMPLES The present invention will be described below with reference to examples and comparative examples using conventional formulations.

Example 1 Novolak type phenol resin was used as a thermosetting resin at 35.
% By weight, 5% by weight of hexamethylenetetramine as a curing agent, 55% by weight of glass fiber as an inorganic filler, and 5% by weight of a pigment and the like as other additives. After uniformly mixing them, heat them with a mixing roll. The mixture was kneaded and pulverized to obtain a molding material. While stirring this molding material with a mixer, a three-fold water diluent (concentration of zinc stearate: 15% by weight) of an aqueous dispersion of zinc stearate (trade name: FCO DISPER ZD) is sprayed and mixed, and the desired molding material is mixed. Was manufactured. The amount of the aqueous zinc stearate dispersion added was such that 0.1% by weight of zinc stearate was added to the molding material. In this manufacturing process, after the addition of the aqueous dispersion of zinc stearate, the molding material was transported by air and packed in a bag. The water content of the molding material was 0.6%.

Comparative Example 1 Using the same raw material as in Example 1, kneading and pulverizing in the same manner and stirring the obtained molding material with a mixer, powdered zinc stearate was added to the molding material in an amount of 0%. 0.1% by weight was added and mixed to produce a molding material. As in the example, in this production step, after the addition of the aqueous dispersion of zinc stearate, the molding material was aired and packed in bags. The water content of the molding material was 0.2%.

Comparative Example 2 A molding material was produced in the same manner as in Comparative Example 1, except that the amount of solid zinc stearate added was 0.2% by weight based on the molding material. The water content of the molding material was 0.2%.

Comparative Example 3 A molding material was produced in the same manner as in Comparative Example 2 except that the content of water in the molding material was adjusted to 0.6% by weight.

With respect to the molding material obtained as described above, the residual amount of zinc stearate, the moldability, such as heat stability in an injection molding machine, the filling property into a mold, and the molding shrinkage, The Charpy impact strength and bending strength were measured. Table 1 shows the results.

Table 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Material properties Amount of zinc stearate (% by weight) 0.07 0.15 0.16 0.09 Moldability Fillability × × ○ ○ Thermal stability (Min) 10 15 17 20 Molded product characteristics Mold shrinkage (%) 0.25 0.25 0.26 0.26 Charpy impact strength (KJ / m ² ) 5.0 5.0 5.0 5.0 Flexural strength (MPa) 200 200 200 200

(Measurement method) Amount of zinc stearate: The amount of zinc stearate in the molding material obtained through the air transportation step was determined. 2. Filling property: Filling property was evaluated by injection molding. (Molding conditions: mold temperature 180 ° C., curing time 30 seconds) ○: good, ×: unfilled Thermal stability: injection molding cylinder head (temperature:
(At 90 ° C.) in contact with a mold (temperature: 180 ° C.) for a predetermined period of time, and the time during which a filling failure occurred was measured. The longer the time, the better the thermal stability. 4. Molded article characteristics: A test piece for measuring a molded article was prepared by transfer molding (molding condition: mold temperature: 175 ° C., curing time: 3 minutes), and the evaluation method was based on JIS K 6911.

[0019]

As is clear from the above Examples and Comparative Examples, the thermosetting resin molding material of the present invention can be molded by a molding machine having a screw-type preheating section (plasticizing section) such as an injection molding machine. In the above, the thermal stability is good and the filling property into the mold is good. Therefore, the present invention greatly contributes to improvement of the moldability of the thermosetting resin molding material.

Claims (3)

[Claims] An inorganic filler and / or an organic filler is added as an essential component to a thermosetting resin, heated and kneaded, and then an aqueous dispersion of a metallic soap is added to a pulverized molding material. Thermosetting resin molding material. 2. The thermosetting resin molding material according to claim 1, wherein an aqueous dispersion of the metal soap is added to the entire molding material in an amount of 0.1 to 1% by weight as the metal soap in the aqueous dispersion. 3. The thermosetting resin molding material according to claim 1, wherein the concentration of the metal soap in the aqueous dispersion of the metal soap is 10 to 30% by weight.